With the demands in speeding-up, miniaturization or the like in the recent years, a toner capable of fixing at an even lower temperature is in demand. In order to meet this demand, toners in which a crystalline resin and an amorphous resin are used as resin binders are proposed.
For example, proposals for such toners include:
a toner containing a crystalline polyester having a softening point of from 85° to 150° C., obtained by polycondensing an alcohol component containing a diol having 2 to 6 carbon atoms in an amount of 80% by mol or more and a carboxylic acid component containing fumaric acid in an amount of 80% by mol or more, and an amorphous polyester, wherein a crystalline polyester/amorphous polyester weight ratio is from 1/99 to 50/50 (see Japanese Patent Laid-Open No. 2001-222138);
a toner containing a resin binder containing a crystalline polyester and an amorphous polyester, wherein the crystalline polyester is contained in an amount of from 1 to 40% by weight of the resin binder, and wherein 90% of dispersed domains of the crystalline polyester have a diameter of from 0.1 to 2 μm (Japanese Patent Laid-Open No. 2002-287426); and
a toner containing a crystalline polyester having a softening point of from 80° to 130° C., obtained by polycondensing an alcohol component containing an aliphatic diol having 2 to 8 carbon atoms in an amount of 70% by mol or more, and a carboxylic acid component containing an aromatic dicarboxylic acid compound in an amount of 70% by mol or more, and an amorphous polyester obtained by polycondensing an alcohol component containing an alkylene oxide adduct of bisphenol A in an amount of 70% by mol or more, and a carboxylic acid component, wherein a crystalline polyester/amorphous polyester weight ratio is from 5/95 to 50/50 (see Japanese Patent Laid-Open No. 2005-300867).
In addition, proposals are made on
a toner binder comprising 0.5 to 50% by weight of a crystalline polyester having a melting point of from 50° to 120° C., a melt viscosity at 150° C. of from 5 to 1,000 centi-Poises, a hydroxyl value of 5 or less, and an acid value of 20 or less, and 50 to 99.5% by weight of a resin binder having a glass transition temperature of from 50° to 100° C. (see, Japanese Patent Laid-Open No. Hei-11-249339), and
a toner containing a crystalline polyester, an amorphous polyester, a black metal material having a saturation magnetization of 50 emu/g or less (see, Japanese Patent Laid-Open No. 2004-245887).